Soil: Keeping nutrients in food and carbon in the ground

UNITED NATIONS, New York: Healthy soil not only makes food more nutritious it also helps keep carbon out of the atmosphere by storing it underground.

Yet around the world over 500 million hectares of soil has become degraded—leading to the loss of valuable nutrients as well as the release of carbon, speeding up the process of man-made climate change.

IPS spoke to Caon at an event ahead of World Soil Day, which was marked on Monday, December 5.
The event focused on the special role of pulses in preserving soils.

2016 is International Year of Pulses, following on from 2015, which was the International Year of Soil.
Pulses include peas, beans, chickpeas and lentils. They are particularly popular in South Asia and Latin America.

Pulses are generally more popular in developing countries than developed countries, Caon noted.
“Seventy five percent of pulses are consumed in developing countries and only 25 percent in developed countries,” she said.

Pulses are good for nutrition and income, particularly for women farmers who look after household food security, like those shown here at a village outside Lusaka, Zambia. Credit: Busani Bafana/IPS
According to the FAO, pulse crops are one of the most sustainable crops a farmer can grow.

“Pulses are a very good ally in combatting and adapting to climate change because of the soil organic matter content they provide to the soil,” said Caon.

“Pulses have deep root systems which basically once you harvest the plants, or the root dies, keep the carbon in the soil,” she added.

Plants also keep carbon in the soil in other ways, said Caon. Leaves that fall from the plants are taken back up into the soil as organic carbon, while plants also stimulate microbial activity fostering additional organic matter.

“Soil organic matter is basically constituted by the leaves and organisms,” said Caon. “It’s really a form in which carbon can be taken into the ground and not into the atmosphere in the form of carbon dioxide which causes climate change and the greenhouse gas effect.”

In addition, pulses are much more water efficient than other sources of protein. According to the FAO it can take as little as 43 gallons of water to grow one pound of pulses, compared to 216 gallons for soybeans and 368 gallons for peanuts.